Mining cutter bit



' Nov. ll 194k Filed Dc. so, 1940 N V ENTOR.

75 ATTORN Patented Nov. 11, 1941 UNITED STATES PATENT CFFICE v e2,262,592 f f i MINING CUTTERBIT *A Henry M. Stephens, Montgomery, W.Va.

Application December 30, 1940, Serial No. 372,235

2 Claims.

This invention relates to bit holders and particularly to a miningcutter bit used in connection with the mining of coal and ore or thelike, or in such places as requirethe use of a bit of the type forcutting through a material, and has for its principal object theprovision lof an improved construction of this character which is highlyeicient in use and economical in manui facture.

The present invention relates to an improvement over that shown in mycompanion application led on even date hereof Serial No. 372,233.

Among the salient objects of this invention is the provision of aneffective and inexpensive arrangement for releasably holding and wedgingthe bit to its chuck. n

Heretofore in the employment of mining cutter bits of the typehereinafter described, due to the lack of firmness in holding the bit inplace, a vibratory action would be transmitted to the bit, ultimatelyresulting in crystallization of the shank thereof and the breakage ordislodgement of the bit from its chuck or holder. In many instances inbits of the type hereinafter set forth, by virtue of the particular andspecial means adapted for holding the bit in its place upon the chuck,either the chuck or the shank of the bit, in order to make room for theattachment, was greatly weakened and often weakened to the point where,when the bit was subjected to rough usage, breakage at the line ofweakened union occurred.

It is therefore one of the many objects of this invention to provide abit which is attached to the chuck holder in a manner such as willprevent these known disadvantages.

Other objects will appear hereinafter.

The invention consists in the novel combination and arrangement of partsto be hereinafter described and claimed.

The invention will be best understood by reference to the accompanyingdrawing showing the preferred form of construction, and in which:

Fig. 1 is an edge view of the invention;

Fig. 2 is a plan sectional detail View of the same;

Fig. 3 is a perspective view of the tool holder embodying my invention;and

Fig. 4 is a sectional detail view of the same taken substantially online 4--4 of Fig. 2.

In carrying my invention into effect, I provide a tool holder Icomprising a head I I and a shank I2. This shank I2 is adapted to beslidably received in a socket I3 formed in a chuck I4 having the usualeyelets I5 whereby a number of the chucks may be attached together inchain formation in a manner and for the purposes well known in the art.

This shank I2 is provided with a tapering recess IB into which isprojected a set screw II threaded into the chuck I 4. The arrangement issuch that by partial withdrawal or loosening of the set screw I'I, thetool holder I0 may be moved a predetermined distance from its innermostposition with respect to the chuck I4.

The head II is provided with a tool receiving socket I8 adapted toreceive a tool I9 which in the present instance is in the form of acutter bit. The tool socket I8 and cutter bit I9, in the preferred formof construction as illustrated in the drawing, each have a substantiallytriangular configuration whereby the cutter bit I9, when inserted in thehead I0, is inserted into the tool socket and withdrawn therefrom in thesame direction.

Means is provided for releasably wedgin'g the cutter bit I9 in thesocket I8, and this means provides a transversely slidably mounted wedge20 having one side Wall 2| thereof tapered for wedging action withintheslot 22, within which it is positioned, and against the adjacent edge23 of the -cutter bit I9, the point of contact for strengtheningpurposes being substantially adjacent the apex 24 of the cutter bit I9.The wedge 20 is provided with an undercut portion 25, and adjacent thisundercut portion 25, when the wedge is mounted in the wedging positionas shown in Fig. 4, the edge of the slot 22 adjacent thereto issubstantially beveled as at 26, so that an instrument 21, such as ascrewdriver or the like, may have its tip 28 projected into the undercut.25 to force the withdrawal of the wedge 20, the beveled edge 26 servingas a point of leverage for the tool 21 for this operation.

In this construction, it may be seen that the cutter bit may be removedfrom the head II without removing the tool holder I0 from its fixedposition with respect to the chuck; that the wedge is so related withrespect to the head II and the cutter bit I9 that no part of eitherelement is weakened.

This wedging means is substantially simple in construction, andtherefore results in economical manufacture.

, While I have illustrated and described the preferred form ofconstruction for carrying my invention into effect, this is capable ofvariation and modification without departing from the spirit of theinvention. I, therefore, do not wish to be limited to the precisedetails of construcwedge member mounted n said slot and havinga bevelededge adapted to wedge against the cutter' .f

bit adjacent the apex thereof for Wedging the cutter bit in said toolslot.

2. In combination, a tool holder comprising a f head having a toolreceiving slot of substantially triangular formation in plan View, acutter bit adapted to be mounted in said slot and being substantiallytriangular shaped in plan View, said head being provided with atransversely extending opening communicating with the tool slot, a Wedgemember mounted in said slot and having a beveled edge adapted to wedgeagainst the cutter bit adjacent the apex thereof for wedging s thecutter bit in said tool slot.

HENRY M. STEPHENS.

